Sundaram (Nagesh) is a server in Greenlands Hotel (Chennai), owned by Chakravarthy (Major Sunderrajan). Sundaram's talent and wit attract customers and also irritates a few. Radha (K.R. Vijaya), a college student, and her friends are on an excursion to Mahabalipuram and he waits for their table. She appreciates him and Sundaram misunderstands her affection as love and starts fantasizing about her. Subsequently, Radha visits the hotel for breakfast and he understands that Radha is Chakravarthy's daughter.
One day, Raghavan (R. Muthuraman) visits the hotel with his friend Sugumar (Raja), a film producer, and notices his schoolmate Sundaram. Both are surprised to see each other but do not reveal their friendship before Sugumar. Later, Raghavan meets him and they both recall their deep friendship and exchange notes on their lives.
Through his hard work and education, Raghavan has risen to the level of a Manager. But Sundaram, who had received widespread appreciation for his acting skills, quit studies and started seeking roles in films. He says that even after four years of struggle, he hasn't got an opportunity yet.
During their subsequent meetings, Sundaram keeps talking about Radha (without mentioning her name). Raghavan genuinely believes that this girl may be in love with Sundaram and motivates him to proceed further. One day, when Raghavan is getting ready to meet a prospective bride (Radha), Sundaram comes there and describes the girl he was talking about. Realising that Sundaram is talking about the same girl Radha, whom he is going to see as his bride, Raghavan decides not to meet her and decides to work towards raising Sundaram's economic status on par with Radha's father so that his friend can attain his love.
Raghavan takes Sundaram to his film producer friend Sugumar seeking a role for him. Based on Sundaram's simple appearance, Sugumar rejects him. However, when Sundaram demonstrates his acting skills in an intelligent and convincing manner, Sugumar sees great potential and agrees to sign him for his next film. By then, another producer, who was with Sugumar, pays an advance and signs Sundaram for his film.
Radha comes to congratulate him and Sundaram is delighted. He introduces her to Raghavan and goes inside to get some snacks. Radha angrily asks Raghavan why he did not turn up to meet her on the appointed day. Raghavan is confused and states that he was under the impression that she loves Sundaram. Shocked, Radha explains that she likes Sundaram for his innocence but never had any romantic feelings for him. Raghavan is pleasantly surprised but to ensure that his friend's budding acting career does not suffer due to this truth, he requests Radha to continue her earlier behavior to ensure that Sundaram succeeds and Radha agrees.
Sundaram's debut film Appavi Kanavan (Innocent Husband) becomes a hit. He gets many offers and soon becomes a popular comedy actor and very wealthy. His mother (S.N. Lakshmi) misses him and-expresses her desire that she should die in his arms. In spite of his wealth and fame, Sundaram remains humble and grounded. He displays his server uniform in the centre of his house as a reminder of his past life. Meanwhile, Raghavan strongly believes that Sundaram will gradually forget Radha so that they can get married without any hitch. But on the contrary, Sundaram's love and desire for Radha grows and he seeks Raghavan's help to express his love.
Raghavan informs Radha of his inability to backstab Sundaram and requests her to marry Sundaram, but she refuses and offers to personally explain her feelings to Sundaram. One day, when Sundaram expresses his love, Radha declines and explains that she never imagined that he would assume her affection to be love. Sundaram is shattered, as all his dreams and hard work has collapsed. However, he consoles himself when he comes to know that she loves Raghavan. Sundaram meets Raghavan, puts him at ease and advises him to marry Radha soon.
One day, Sundaram is busy shooting the climax scene of a film and the director instructs not to allow anyone inside the set. Sundaram's mother falls down the stairs and is injured badly. Sundaram's manager Manickam tries to convey this news, but he isn't allowed. Sundaram struggles with the final scene, gives his best shot and comes out of the studio, only to be informed that his mother is seriously injured. He rushes home, but by then she is no more. Sundaram, shattered after losing out on love, is now devastated to lose his mother too.
When Raghavan and Radha get married, Sundaram greets them and requests them not to name their child as Sundaram, as it is an unlucky name. He then changes into his old server uniform and goes back to serve people at the function. When Raghavan protests, Sundaram states that the server uniform is permanent, while the actor role was temporary.
[from the book Pride of Tamil Cinema:1931 to 2013 by G Dhananjayan, Blue Ocean Publishers, 2014]